DE 199 28 913 A1 has disclosed a piston pump, in which, in a pump housing, a single pump element or a pump unit is formed by a piston which is mounted displaceably in a cylinder bore of a cylinder. The piston sucks brake fluid through a feed opening into the cylinder bore and conveys it out of the cylinder bore through an outlet opening. The piston is pushed into the cylinder bore and is sealed therein with respect to the cylinder by means of a sealing element. Said sealing element is also called a high pressure seal.
Pistons of known piston pumps have a first piston section partially as a first component, on which first piston section a valve seat for an inlet valve is situated. As a second, separate component, pistons of this type have a second piston section which forms the actual piston rod. Said piston rod is driven as a rule by means of an eccentric.